The present invention relates to reactive dye compounds. In particular the present invention relates to reactive dye compounds having improved dye-bath Exhaustion (E) and improved dye-fibre covalent Fixation (F).
Reactive dye compounds are known in the art for dyeing various substrates. Such substrates include for example proteinaceous materials such as keratin, e.g. found in hair, skin and nails and various animal body parts such as horns, hooves and feathers, and other naturally occurring protein containing materials, e.g. silk and saccharide-derived materials such as those derived from cellulose or cellulose derivatives, e.g. natural products such as cotton, and synthetic fibres such as polyamides.
Examples of classes of such reactive dyes which are well known in the art include dyes containing a vinyl sulphone group or vinyl sulphone precursor groups such as those commercially available from Dystar under the tradename Remazol.
There are many different types of commercially-available reactive dyes for dyeing cellulosic and polyamide-type substrates. However, a critical problem still filing the textile dye industry today is the significant level of dyestuff material which remains in the effluent waste water after the dyeing process is finished. The industry measure for this problem is known as dye-bath Exhaustion (E). A high Exhaustion value for a particular dye compound means that a low level of spent dye renains in the effluent after the dyeing process is complete, while a low Exhaustion value means that a high level of spent dye remains in the effluent. There is clearly a need therefore for new dye compounds which have higher Exhaustion Values compared with commercially available dye compounds, and which provide benefits in terms of reducing levels of spent dyestuff in effluent water.
As well as having a high Exhaustion Value, it is also important for a dye compound to have a high dye-fibre covalent Fixation Value (F). The Fixation Value (F) of a reactive dye compound is a measure of the extent of covalent bonding with the substrate based on the dye originally absorbed during the dyeing process. Thus 100% Fixation means that 100% of the absorbed dye covalently bonds to the substrate. Thus, there is clearly a need to provide dye compounds having increased Fixation Values. A high Fixation Value can result in a simplification of the post dyeing xe2x80x9csoaping off processxe2x80x9d traditionally associated with fiber reactive dye compounds. In particular, a high Fixation Value can result in a reduced time spent on the xe2x80x9csoaping off processxe2x80x9d together with a reduced cost.
It has now been surprisingly found that a new class of fibre reactive dye compounds derived from vinyl sulphone dyes and their precursors such as chloroethylsulphone, sulphatoethylsulphone, phosphoethylsulphone, and other blocked ethyl sulphones as known in the art, comprising at least one chromophore group, at least one SO2C2H4 group and at least one A(Cxe2x95x90O)R* group, such as citrate, exhibit significantly increased values of Exhaustion (E) and Fixation (F). These dyes can be used on a wide variety of substrates. They are particularly useful for cellulosic substrates, such as cotton, and show significant improvements in terms of decreasing the amount of spent dyestuff in effluent, increasing dye affinity to the substrate, increasing the efficiency of the dye-substrate covalent reaction, and simplifying the post dyeing xe2x80x9csoaping off processxe2x80x9d traditionally associated with reactive dyes. In addition, the compounds of the present invention provide significantly more intense dyeings, and can be used for both high and low temperature dyeing, hence reducing the cost of the dyeing process. Furthermore, the compounds of the present invention can be used together with specific chromophores for cellulose substrate dyeing leading to significantly reduced levels of salt needed for dyeing.
According to the present invention there is provided a reactive dye compound comprising:
(a) at least one chromophoric moiety
(b) at least one SO2C2H4 group which is attached to the chromophoric moiety either directly via the sulphur atom of the SO2C2H4 group or via a linking group L;
characterised in that at least one SO2C2H4 group is attached to at least one Y group on its terminal carbon atom wherein Y is xe2x80x94A(CO)R*, wherein A is selected from O or S, preferably O, and wherein R* is an organic residue which contains at least one nucleophilic group, wherein the nucleophilic group is preferably selected from OH, NH2, SH, COOH, xe2x80x94Nxe2x80x94, NHR1 and NR1R2 wherein R1 and R2 may be the same of different and may be selected from C1-C4 alkyl.
The compounds of the present invention exhibit increased Exhaustion (E), Fixation (F) and Efficiency (T) values and provide improvements in terms of reducing spent dyestuff in effluent, increasing dye affinity to the substrate, increasing the efficiency of the dye-substrate covalent reaction, ability to cany out the long-liquor dyeing process at room temperature as well as at elevated temperatures, and simplifying the post dyeing xe2x80x9csoaping off processxe2x80x9d traditionally associated with fiber reactive dyes. In addition, the compounds of the present invention provide significantly more intense dyeings, i.e. greater colour intensity in the dyed substrate, without compromising levelness. Typical Exhaustion Values for the compounds and products herein are greater than 95%. Typical Fixation Values for the compounds and products herein are greater than 95%.
As used herein the term xe2x80x9creactive dyexe2x80x9d means a dye containing one or more reactive groups, capable of forming covalent bonds with the substrate to be dyed, or a dye which forms such a reactive group in situ.
As used herein the term xe2x80x9cExhaustionxe2x80x9d in relation to reactive dyes means the percentage of dye which is transferred from a solution of the dye to the substrate to be treated at the end of the dyeing process, before rinsing and soaping. Thus 100% Exhaustion means that 100% of the dye is transferred from the dye solution to the substrate.
As used herein the term xe2x80x9cfixationxe2x80x9d in relation to reactive dyes means the percentage of dye which covalently bonds with the substrate, based on the dye originally absorbed during the dyeing process. Thus 100% Fixation means that 100% of the dye absorbed is covalently bonded with the substrate.
The total efficiency of reactive dyes can be measured by their Efficiency Value (T) which can be calculated from the Exhaustion Value (E) and Fixation Value (F) using the following equation:
%T=(Fxc3x97E)/100
The compounds of the present invention comprise a chromophoric moiety, at least one SO2C2H4 group linked to the chromophore group either directly via the sulphur atom or via a linking group L and a A(Cxe2x95x90O)R* group wherein A is selected from O or S, and R* is an organic residue comprising at least one nucleophilic group.
Chromophoric Moiety
The reactive dye compounds herein can comprise one or more chromophoric moieties (O). In reactive dye compounds comprising two or more chromophoric moieties these can be the same or different. Preferably the reactive dye compounds herein comprise from one to three chromophoric moieties, preferably one or two chromophoric moieties, preferably one.
Any chromophoric moieties suitable for use for dyeing substrates can be used in the present invention. The term chromophore as used herein means any photoactive compound and includes any coloured or non-coloured light absorbing species, e.g. fluorescent brighteners, UV absorbers, IR absorbing dyes.
Suitable chrornophoric moieties for use in the dye compounds herein include the radicals of monoazo, disazo or polyazo dyes or of heavy metal complex azo dye derived therefrom or of an anthraquinone, phthalocyanine, fonnazan, azomethine, dioxazine, phenazine, stilbene, triphenylmethane, xanthene, thioxanthene, nitroaryl, naphthoquinone, pyrenequinone or perylenetetracarbimide dye.
Suitable chromophoric moieties for use in the dye compounds herein include those disclosed in EP-A-0,735,107 (Ciba-Geigy), incorporated herein by reference, including the radicals described therein which contain substituents customary for organic dyes, such as sulphonate substituents which enhance the water solubility of the dye compound.
Most preferred chromophoric D groups for use herein are polysulphonated azo chromophores such as those present in Procion (RTM) dyes commercially available from BASF, Drimalan (RTM) dyes commercially available from Clariant, Drimarene (RTM) dyes commercially available from Clanant and Levafix (RTM) and Remazol (RTM) commercially available from Dystar.
A(Cxe2x95x90O)R* group
At least one of the SO2C2H4 groups is substituted on the terminal carbon atom with at least one xe2x80x94A(Cxe2x95x90O)R* group wherein A is selected from O Se or S, preferably S or O, more preferably O, wherein R* is an organic residue containing at least one nucleophilic group. As used herein the term xe2x80x9cnucleophilic groupxe2x80x9d means a negative ion or any neutral molecule that has an unshared electron pair. Suitable nucleophilic groups herein include OH, NH2, SH, COOH, xe2x80x94Nxe2x95x90, NHR1 and NR1R2 wherein R1 and R2 may be the same of different and may be selected from C1-C4 alkly.
Suitable R* groups for use herein are alkyl or aryl residues which contain at least one nucleophilic group. Preferably the R* groups herein are selected from the following groups each substituted with or containing at least one nucleophilic group: substituted or unsubstituted, straight chain or branched chain C1-C8 alkyl, substituted or unsubstituted straight chain or branched chain C2-C8 alkenyl having at least one olefinic group, substituted or unsubstituted, saturated or unsaturated or aromatic 3-9 atom monocyclic carbocycle or substituted or unsubstituted, saturated or unsaturated or aromatic 7-17 polycyclic carbcycle, substituted or unsubstituted, saturated or unsaturated or aromatic 3-9 atom monocyclic heterocycle or substituted or unsubstituted, saturated or unsaturated or aromatic 7-17 atom polycyclic heterocycle, wherein said heterocycle has one or more heteroatoms selected from O, N or S.
In the definition of R* above, where the term xe2x80x9csubstitutedxe2x80x9d is used such substitution may be with one or more substituents. Such substituents include, but are not limited to, those listed in C. Hansch and A. Leo, Substituent Constants for Correlation Analysis in Chemistry and Biology (1979), hereby incorporated by reference herein. Preferred substituents include, but are not limited to, alkyl, alkenyl, alkoxy, hydroxy, oxo, amino, aminoalkyl (e.g. aminomethyl, etc.), cyano, halo, carboxy, alkoxyacetyl (e.g. carboethoxy, etc.), thio, aryl, cycloalkyl, heteroaryl, hetcrocycloalkyl, (e.g.piperidinyl, morpholinyl, piperazinyl, pyrrolidinyl, etc.), imino thioxo, hydroxyalkyl, aryloxy, arylalkyl, and combinations thereof.
Preferred R* groups for use herein include, but are not limited to, CF3, (CH2)nSH, (CH2)nNH2, CH(CH3)OH, C(OH)(CH2COOH)2, CH2C(OH)(CO2H)CH2COOH, 2-aminophenyl, 2-hydroxynaphthyl 2-pyrrolidyl, CH2SSCH2CO3xe2x88x92, (CH2)nxe2x80x94SO3xe2x88x92, C(OH)(H)CH2COOH, CH2C(H)(OH)COOH, C(OH)(H)C(OH)(H)COOH, derivatives of hydroxy carboxylic acid polymerisation (e.g. in the case of polymerisation of two lactic acid molecules R* is CH(CH3)O(CO)CH(CH3)OH), (CH2)nNHR1, CH2NH1R2, CH2NHNH2, CH2NHOH, CH2SMe, CH(NH2)(CH2)n(COOH), CH(NH2)CH2SMe, CH(NH2)CH2SSCH2CH(NH2)COOH, CH(NH2)CH2SO3H, C6H4OH, C6H4COOH, C6H4NH2, C5H4N, (CH2)nC5H4N, CH(R#)NH2, (CH2)nxe2x80x94SSO3xe2x88x92, (CH2)nxe2x80x94Sxe2x80x94Sxe2x80x94(CH2)n, xe2x80x94C(OH)(COOH)CH2COOH, peptide or polypeptide, wherein R1 and R2 is independently selected from C1-C4 alkyl, wherein n is an integer in the range of 1 to 4 wherein within the same molecule n is not necessarily the same integer and where R# corresponds to an amino acid sidechain. For examples of such amino acids, cf. xe2x80x9cOrganic Chemistryxe2x80x9d by Graham Solomons, 5th Edition, Wiley, N.Y., 1992, p1094-1095.
Preferred R* groups for use herein are selected from (CH2)nSH, (CH2)nNH2, C5H4N, CH(CH3)OH, C(OH)(CH2COOH)2, CH2C(OH)(COOH)CH2COOH, CH(R#)NH2, CH(CH3)OH, CH(OH)CH2COOH, CH2C(H)(OH)COOH, C(H)(OH)C(H)(OH)COOH, C6H4OH, C6H4NH2 and C5H4N.
Particularly preferred R* groups herein are groups derived from hydroxy carboxylic acids such as citric acid, lactic acid, tataric acid, malic acid, salicylic acid, and the like, including structural isomers thereof (e.g. in the case of citric acid R* can be C(OH)(CH2COOH)2 and CH2C(OH)(COOH)CH2COOH) and polymers thereof (e.g. in the case of polymerisation of two lactic acid molecules R* is CH(CH3)O(CO)CH(CH3)OH.
Particularly preferred R* group from the viewpoint of providing reactive dye compounds having excellent dye properties are those derived from citric acid, including C(OH)(CH2COOH)2 and CH2C(OH)(COOH)CH2COOH. It will be understood by those skilled in the art that in the case of unsymmetrical compounds having more than one carboxylic acid group, for example, citric acid and malic acid, that a mixture of dye compounds will be obtained due to there being different carboxylic acid reactive groups in the molecule which can attach to the heterocyclic ring. It is also to be noted that for R* groups which are hydroxy-terminated, such as for example lactic acid or citric acid, it is possible for polyester formation to occur via reaction of the lactic acid moiety (or citric acid) with another lactic acid (or citric acid) moiety. In the case of lactic acid polymensation of two lactic acid molecules therefore the R* group would be CH(CH3)O(CO)CH(CH3)OH. Depending on the reaction conditions therefore, a mixture of dye compounds can be obtained, for example in the case of citric acid, a mixture of one or more of the monocitrate compounds (there could be two different isomers of these depending on which carboxylic acid group attaches to the heterocyclic ring), bis-citrate compounds (including different structural isomers), and compounds formed from a citric acid polymer.
Without wishing to be bound by theory, it is believed that high fixation values for the reactive dye compounds herein derived from hydroxy carboxylic acids such as citric acid is the result of preferential bonding of the reactive dye to nucleophiles on the fibre vis a vis nucleophiles in solution. Additionally, any hydrolysed dye may be reactivated by carboxylic acids present in solution.
Preferred reactive dye compounds of the present invention may be represented by the following formula (I): 
wherein:
D is a chromophore group;
r is 0 or 1;
L is a linking group selected from NH, (CH2)n, Nxe2x80x94(CH2)nN, xe2x80x94(CH2)nxe2x80x94N, 
xe2x80x83wherein
Ar is an aryl group, preferably benzene, Y is halogen or O(Cxe2x95x90O)R*, n is an integer of from 1 to 4, Z is a nitrogen-containing heterocycle, X is selected from thio-derivatives, halogen (preferably fluorine and chlorine), amiines, alkoxy groups, carboxylic acid groups, CN, N3, and quaternized nitrogen derivatives, Q+;
A is O or S,
R* is selected from (CH2)nSH, (CH2)nNH2, CH(CH3)OH, C(OH)(CH2COOH)2, CH2C(OH)(CO2H)CH2COOH, C(OH)(H)CH2COOH, CH2C(H)(OH)COOH, C(OH)(H)C(OH)(H)COOH, derivatives of hydroxy carboxylic acid polymerisation (e.g. in the case of polymerisation of two lactic acid molecules R* is CH(CH3)O(CO)CH(CH3)OH), (CH2)nNHR1, CH2NR1R2, CH2NHNH2, CH2NHOH, CH2SMe, CH(NH2)(CH2)n(COOH), CH(NH2)CH2SMe, CH(NH2)CH2SSCH2CH(NH2)COOH, CH(NH2)CH2SO3H, C6H4OH, C6H4COOH, C6H4NH2, C5H4N, (CH2)nC5H4N, CH(R#)NH2, (CH2)nxe2x80x94SSO3xe2x88x92, (CH2)nxe2x80x94Sxe2x80x94Sxe2x80x94(CH2)n, peptide or polypeptide, wherein R1 and R2 is independently selected from C1-C4 alkyl, wherein n is an integer in the range of 1 to 4 wherein within the same molecule n is not necessarily the same integer and where R# corresponds to an amino acid sidechain.
Nitroyen-containing Heterocycle (Z)
Suitable nitrogen containing heterocycles for use herein include monocyclic, bicyclic or polycyclic, unsaturated heterocycles containing at least one nitrogen heteroatom. When monocyclic rings are used, they are preferably selected from unsaturated rings having from about 3 to about 7 ring atoms, especially 5 or 6 ring atoms, comprising from about 1 to about 3 nitrogen beteroatoms, prefaably 2 or 3 nitrogen heteroatonms When bicyclic heterocycles are used, they preferably comprise an unsated nitrogen containing heterocycle having 3 to 7 ring atoms, preferably an unsaturated nitrogen containing heterocycle having 5 or 6 ring atoms comprising 1 or 2 nitrogen atoms, fuse to a 5 to 7 membered carbocycle preferably a 6-membered unsaturated carbocycle. When bicyclic heterocycles are used, the oxy carbonyl substituents are preferably attached to the nitrogen containing heterocyclic ring.
Preferred for use herein are 5 or 6 membered unsaturated nitrogen containing monocyclic heterocyclic rings comprising 2 or 3 nitrogen heteroatoms or bicyclic rings containing a 5 or 6 membered unsaturated heterocyclic ring containing 2 nitrogen heteroatom fused to a 6 membered unsaturated carbocycle.
Examples of suitable heterocycles for use herein include, but are not necessarily limited to triazine, pyrimidine, quinoxaline, pyrimidinone, phthalazine, pyridazone and pyrazine.
Preferred for use in the compounds herein are triazine, pyrimidine and quinoxaline.
Suitable thio-derivatives for use herein include, but are not necessarily limited to groups baving the formula SRxe2x80x2 wherein Rxe2x80x2 is selected from H or alkyl or preferably short chain alkyl (preferably less than about 6 carbon atoms), alkanol, alkyl carboxylate, alkylamide, alkylsulphonate, alkyl phosphonate, alkyl thiosulphonate, alkylamine, alkyl thiosulphate, aryl sulpbonate, aryl carboxylate, aryl phosphate, aryl amine, cyanates, sulphonates, branched alkyl thio carboxylates, branched alkanol thiols, guanides, alkyl-xcex1-(amino-xcex1-carboxylate, (di) thio alkyl esters of glycerol, alkyl thiol alkyi esters of glycerol, alkyl esters, mono thio diesters, thiol alkyl esters of ethylene glycol, alkyl thioi alkyl ester of ethylene glycol and alkyl thiolipoates. Preferably Rxe2x80x2 is selected from alkyl carboxylates, alkanols and alkylamines.
Examples of suitable thio-derivatives include SRxe2x80x2 groups where Rxe2x80x2 is selected from C1-C4 alkyl, (CH2)nCOOH, (CH2)nCONH2, (CH2)nSO3H, (CH2)nCOOM, (CH2)nPO3H, (CH2)nOH, (CH2)nSSO3xe2x88x92, (CH2)nNRxe2x80x32, (CH2)nN+Rxe2x80x33, PhSSO3xe2x88x92, PhSO3H, PhPO3H, PhNRxe2x80x32, PhN+Rxe2x80x33, xe2x80x94CN, SO3xe2x88x92, (CH2)2CH(SH)Rxe2x80x3(CH2)3COOH, xe2x80x94CH2CHOHCH2SH, and 
n is an integer in the range of 1 to 4 wherein within the same molecule n is not fnecessarily the same integer, and M is a cation of alkaline ear metal , alkali metal, NH4+ or NRxe2x80x33+ and wherein Rxe2x80x3 is C1-C4 alkyl.
Preferred thiodenvatives for use herein have the formula SRxe2x80x2 wherein Rxe2x80x2 is (CH2)nCOOH, (CH2)nOH, and (COOH)CH2CH2(COOH), wherein n is an integer from 1 to 4.
Especially preferred for use herein are thioglycolate (Rxe2x80x2=CH2COOH) thioethanol (Rxe2x80x2=(CH2)2OH) and thiosuccinate (Rxe2x80x2=(COOH)CH2CH2(COOH)), especially thioglycolate.
Suitable quaternized nitrogen derivatives for use herein can be represented by Q+ wherein Q is selected from amines, :saturated or unsaturated, substituted or unsubstituted nitrogen containing heterocycles having from about 3 to about 8 ring members and comprising at least one nitrogen heteroatom. Preferred substituents are carboxylates, amides, C1-C4 alkyl and alkyl carboxylates.
Particularly preferred for use herein are Q groups selected from:
NRxe2x80x33, 
(CH3)2Nxe2x80x94NH2;
N(CH3)2CH2COOH (dimethylaminobetaine);
N(CH3)2(CH2)nNH2 
N(CH3)2(CH2)nN+Rxe2x80x33;
N(CH3)2CH2CONH2;
wherein Rxe2x80x3 is C1-C4 alkyl and n is an integer of from 1 to 4.
Particularly preferred quaternized nitrogen derivatives for use herein are nicotinate, diazabicyclooctane (DABCO), dimethylaminobetaine and isonicotinate, especially nicotinate.
The quaternized nitrogen derivative is attached to the nitrogen-containing heterocycle via its tertiary nitrogen atom.
Preferred X groups include Y, SRxe2x80x3, halogen (preferably F or C1), NRxe2x80x3H, NRxe2x80x32, ORxe2x80x3, COOH, SCN, SSO3, SO3, NH1R2, CN, N3 and quaternized nitrogen derivatives Q+, wherein Rxe2x80x3 is C1-C8 alkyl, or aryl and wherein Q, R1 and R2 are as defined above.
Particularly preferred X groups for use herein are Y, halogen (fluorine and chlorine) and quaternized nitrogen derivatives.
A particularly preferred reactive dye compound of the present invention wherein the O(Cxe2x95x90O)R* group in formula (I) above is derived from citric acid has the following structure (Ia): 
wherein D, L, r are as defined above.
Another preferred reactive dye compound of the present invention wherein the O(Cxe2x95x90O)R* group in formula (I) above is derived from citric acid has the following structure (Ib). This compound below (Ib) and the compound above (Ia) differ due to a different xe2x80x94COOH group of the citric acid attaching to the xe2x80x94SO2xe2x80x94CH2CH2xe2x80x94 group. 
wherein D, L and r are as defined above.
Other dye compounds according to the present invention may be represented by the formula (II): 
wherein:
D, L, A and R* are the same or different and are as defmed above in relation to formula (I).
Yet other dye compounds according to the present invention may be represented by the formula (III): 
xe2x80x83wherein:
D, L, A are the same or different and are as defined above in relation to formula (I) and R is derived from R* as defined above, for example carboxylic acids having more than one carboxylic acid groups.
Other dye compounds according to the present invention may be represented by the formula (IV): 
wherein:
D, L, A and R* are as defined above in relationito formula (I) and wherein X is selected from thioderivafives, halogen (preferably fluorine and chlorine), amines, alkoxy groups, carboxylic acid groups, CN, N3, and quatemized nitrogen derivatives, Q+.
The present invention fiurthernore relates to processes for the preparation of dyes herein. In general, dyes herein are prepared by a process which comprises the steps of reacting a first starting material (preferably one mole) with a second starting material (preferably one mole), the first starting material comprising at least one chromophore, at least one SO2C2H4 group which is attached to the chromophore group either directly via the sulphur atom of the SO2C2H4 group or via a linking group (for example a Remazol dye), the second starting material comprising an oxy- or thio-carbonyl group (for example citric acid). It is preferable that the reaction is carried out at a pH of between 2 to 8, preferably 3 to 5 and over several hours, preferably 1 to 5 hours, more preferably 2-3 hours.
Compounds herein having the formula (I) are prepared by reacting a first starting material (preferably one mole) with a second starting material (preferably one mole), the first starting material containing a Dxe2x80x94(L)rxe2x80x94SO2xe2x80x94CH2CH2xe2x80x94 group as defined above (for example a Remazol dye, such as Remazol Brill Blue RS commercially available from Dystar), the second starting material containing an A(Cxe2x95x90O)R* group (for example citric acid (polymerized or unpolymerized), lactic acid (polymerized or unpolymerized), salicylic acid, tartaric acid, malic acid, nicotinic acid, isonicotinic acid, etc). It is preferable that the reaction is carried out over several hours (2-5 hours). In the case of hydroxyacids such as citirc acid, lactic acid, tartaric acid, and the like, it is particularly important to add the acid dropwise over several hours, preferably from about 1 to about 5 hours, preferably from about 1 to about 3 hours.
In order to ensure that the second starting material containing the A(Cxe2x95x90O)R* group bonds to the vinyl sulphone group via the oxy-carbonyl or thio-carbonyl group it is preferable to carry out the reaction under acidic conditions, preferably at a pH of from about 1 to about 8, preferably from about 2 to about 8, more preferably from about 3 to about 5.
In general, dyes having the formula (II)-(IV) can be prepared by using the same general chemistry as for dyes of formula (I) by reacting together suitable starting materials, in suitable amounts.
Depending upon the reaction conditions (for example, amounts of each starting material, form of each starting material e.g. in the case of hydroxyacids polymerized/unpolymerized), mixtures of different dye compounds may be obtained in the final product, such mixtures containing for example, products formed from further substitution reactions, structural isomers (e.g. in the case of citric acid which an unsymmetrical molecule having two carboxylic acid groups), products formed from polymerisation of hydroxy acids (e.g. citric acid and lactic acid. In the case of dipolymerized lactic acid for example the R* group will be CH(CH3)O(CO)CH(CH3)OH).
Hence according to another aspect of the present invention there is provided the product obtainable by any of the processes detailed herein.
In particular, there is provided a product obtainable by a process wherein the process comprises the steps of reacting a first starting material (preferably one mole) with a second starting material (preferably one mole), the first starting material comprising at least one chromophore, at least one SO2C2H4 which is attached to the chromophore group either directly via the sulphur atom of the SO2C2H4 group or via a linking group (for example a Remazol dye), the second starting material comprising an oxy- or thio-carbonyl group (for example citric acid). It is preferable that the reaction is carried out at a pH of between 2 to 8, preferably 3 to 5 and over several hours, preferably 1 to 5 hours, more preferably 2xe2x80x943 hours.
The dye compounds herein are suitable for dyeing and printing a wide variety of substrates, such as silk, leather, wool, polyamide fibers and polyurethanes, keratin fibres such as hair, and in particular cellulosic materials, such as the natural cellulose fibres, cotton, linen, hemp and the like, paper, and also cellulose itself and regenerated cellulose, and hydroxyl-containing fibres contained in blend fabrics, for example blends of cotton with polyester or polyamide fibres.
The dye compounds of the present invention can be applied and fixed to the substrate in various ways, in particular in the form of a solid mixture, aqueous dye solutions and printing pastes. Thus according to the present invention there is provided a dye composition comprising one or more of the dye compounds described herein together with any carrier material suitable for use in a dye composition.
Preferred dye compositions herein comprise an acidic buffer material. Any acidic buffer suitable for use in dye compositions can be used herein. An example of a suitable buffer is a mixed phosphate buffer.
When the dye composition herein is in the form of a paste a preferred ingredient is a thickening agent. Any suitable thickening agents suitable for use in reactive dye compositions can be used herein.
When the dye composition is in the form of an aqueous solution or aqueous gel/paste, the dye composition preferably has a pH of from about 2 to about 8, more preferably from 2 to 5, especially from 2 to 3.
The dyeing and printing processes which can be used with the dyes herein are conventional processes which are well known and which have been widely described in the technical and patent literature. The dye compounds herein are suitable for dyeing both by the exhaust method (long liquor) and also by the pad-dyeing method, whereby the goods are impregnated with aqueous, salt-containing or salt-free dye solutions and the dye is fixed after an alkali treatment or in the presence of alkali, if appropriate with the application of heat. The dye compounds herein are also suitable for the cold pad-batch method, after which the dye together with the alkali is applied using a pad-mangle, the fabric hatched on a roll. A dye-fibre covalent reaction occurs over several hours of storage at room temperature. Alternatively, padded or printed goods may be fixed by a steaming process using steam temperatures between 100-130xc2x0 C. After fixing, the dyeings or prints are thoroughly rinsed with cold and hot water, if appropriate with the addition of an agent acting as a dispersant and promoting the diffusion of the non-fixed portions.
Thus in accordance with another aspect of the present invention there is provided a use of the reactive dyes of the present invention for dyeing and printing substrates such as cotton, wool, nylon, silk, keratin, hair, leather, paper and the like. The compounds herein can be used in methods of dyeing all of the substrates listed above by applying an aqueous solution of one or more of the reactive dyes of the present invention to the substrate to be dyed under suitable conditions of pH and temperature.
The following examples serve to illustrate the compounds and compositions of the present invention.
The starting compounds and components given in the examples below can be used in the form of the free acid or in the form of their salts. As discussed above, the products obtained in the examples below may comprise mixtures of different dye compounds. In the Examples below all the starting materials are commercially available. In particular the Remazol dyes are available from Dystar Textilfarben, GmbH and Co., Deutschland KG, BU -R/F and E, Werk Hochst, Building G834, D-65926 Frankfurt am Main, Germany, and the Sumifix dyes are available from Sumitomo Chemical Co. Lt, Mar. 3, 1998, Kasugade-naka, Konohana-ku, Osaka 554, Japan.